[SheLion]

I know what you mean. On submarines the air handling devices drip with yellow/brown goo from the smokers. I remember as a teenager cleaning my car windshield on the inside and the towel turning brown as I wiped.

My fingers must not be conveying what I mean. When smoking was allowed on airplanes, they cleaned the filters regularly. Then, once smoking was banned, the idiots thought that they didn't have to clean the filters as much.

When they do, the filters are filthy dirty. And the passengers are breathing this. Smoking was not the sole culprit. Germs and diseases brought onto the plane by sick passengers is the real culprit.

[WildTurkey]

Then, once smoking was banned, the idiots thought that they didn't have to clean the filters as much.

They probably didn't. Have you ever seen air handling devices serving a group of smokers? Ugly.